Tapered pole and process of forming the same



March 4; 1958 R. P. MOLT 2,825,431

,TAPERED POLE AND PROCESS OF FORMING THE SAME Filed Dec. 2a, 1956INVENTOR;

Unitid Sims Pat nt TAPERED POLE AND PROCESS OF FORMING THE SAME RichardP. Molt, Olympia Fields, Ill., assignor to Standard Railway EquipmentManufacturing Company, Chicago, iii., a corporation of Delaware Thisinvention relates as indicated to a structural member, and moreparticularly to an elongated taper metal unit suitable as a light poleand the like.

In the past light poles have been made by various methods. In oneprocess of manufacture the pole is made by forming a blank of a suitableconfiguration into a truncated cone by bringing the marginal edges ofthe blank together and securing them by welding. This method isunsatisfactory because of distortion'in the final product and theexpenses involved.

It is an object of the present invention to provide an elongatedstructural unit that may be manufactured by a process that eliminatesdistortion in the finished article.

It is a further object of the invention to provide a structural unit ofsuitable rigidity for use as a light pole.

It is a still further object of the invention to provide a structuralunit that is conveniently and inexpensively manufactured.

Further objects and advantages of this invention will become evident asthe description proceeds and from an examination of the accompanyingdrawing which illustrates one embodiment of the invention and in whichsimilar numerals refer to similar parts throughout the several views.

In the drawings:

Figure 1 is a view in elevation of a structural member embodying theinvention;

Figure 2 is an enlarged end view taken along line 22 of Figure 1;

Figure 3 is an enlarged view in section taken along line 3-3 of Figure1;

Figure 4 is an enlarged view in section taken along line 4-4 of Figure1;

Figure 5 is an enlarged end view taken along line 5-5 of Figure 1;

Figure 6 is an enlarged fragmentary view taken along line 66 of Figure1;

Figure 7 is a plan view of a blank that is used in the manufacture of astructural unit of the invention;

Figure 8 is a perspective view of the blank formed into a segment of acylinder;

Figure 9 is a perspective view of two sections of cylindrical segmentfolded along the center line thereof so as to form a pair of wings;

Figure 10 is a perspective view showing a step of welding the top andbottom sections of the convex elements together;

Figure 11 is an end view showing the step of welding the convex memberstogether.

Referring now tothe drawings, reference numeral 10 indicates generally adevice embodying the invention. As best shown in Figures 3 through 5,the structural unit is made up of four elements, 11, 12, 13 and 14, allof which are cylindrical segments identical in shape and configuration.The elements progressively decrease in width along the lengths thereofso as to form a hollow tapered unit when assembled, as shown inFigure 1. All of the elements are joined together at their longitudinal2,825,431 Patented Mar. 4, 8-

edges in a unit which is circular at the base end portion (Fig. 2) andpolygonal at the apex end portion (Fig. 5). Two pairs of elements 11,12, and 13, 14, are integrally joined at the longitudinal edges to maketwo convex members 21, 22. The convex members are secured together atthe meeting longitudinal edges into the structural unit of theinvention, such as by welding.

The convex members 21, 22 are made by forming a segment of a cylinderwhich has the shape of a plane intercepting the cylinder at an angle toits axis (Fig. 8). The convex members are provided (Fig. 9) with acrease 25 parallel to, and preferably along, the center line thereof toform a pair of cylindrical segment wing elements 11, 12 and 13, 14 whichare folded inwardly. The configuration of the wing elements 11, 12, 13,and 14 is that of a segment of a cylinder. In the form shown in thedrawings, the wing elements are folded until the angles formed by thewing elements are equal and the distance between the outer edges of themember is about twice the depth of the convex member. The axes of thewing elements progressively converge uniformly about and toward thelongitudinal axis of the structural unit intersecting said axis at thecircular base thereof.

As shown in Figures 1, 6, 9, and 10, each of the convex members may bemade into two parts, a bottom section 31 and a top section 32, which aresecured together by welding around a strap 34. It should be understood,however, that in some instances it may be desirable to make the convexmembers of a single piece.

In manufacturing the structural unit of the invention, a blank 40 isfirst shaped in the outline of a truncated isosceles triangle, shown inFigure 7. The blank is bent on a cylindrical mandrel into the segment 44of a cylinder as shown in Figure 8. Because the blank is a truncatedisosceles triangle, the segment will take the shape of one formed by aplane cutting the cylinder at an angle to its axis.

A crease is then formed on the cylindrical segment along the center linethereof, as shown in Figure 9, to divide the convex member into a pairof wing elements. It will be noted that in Figure 9, the convex memberis shown in two parts, a bottom 31 and a top 32. These sections arebutt-welded together to form a single assembly, as illustrated in Figure10, or the mating sections may first be assembled by longitudinalbutt-welding and then the two units transversely butt-welded, to formthe complete structure. A strap 34 is placed at the juncture of the topand bottom sections to reinforce it, when the buttweld is made from theoutside.

The two convex members 31, 32 are placed together with the oppositeedges in juxtaposition about a back-up gauge 5i as best shown in Figure11. The gauge maintains the opposite wing segments spaced equally. Thewings of the convex members are then forced inwardly by clamps 51 whilethe Welding operation takes place. The two convex elements are securedtogether by weld- .ing at 23, 24 along the longitudinal opposite edgesthereof.

In the drawing and specification there has been set forth one embodimentof the invention, and although specific terms are employed, they areused in a generic and descriptive sense only and not for purposes oflimitation. Changes in form and in the proportion of parts, as well asthe substitution of equivalents are contemplated, as circumstances maysuggest or render expedient, without departing from the spirit or scopeof this invention as further defined in the following claims.

I claim:

1. An elongated hollow tapered structural unit comprising at least threeidentical cylindrical segments, each of said segments progressivelydecreasing in width along the length, wherein each segment is joined toadjacent seglongitudinal axisof the structural unit at the circulal end2.efln' elongated{hollow tapered 'stru ctural unit' com;

prising atleafst'three? identical cylindrical segment's, each" 7 of saidsegments progressively decreasing in width'alon therlength, whereineach'segme'nt"is'joined to adjacent segments at'ithe longitudinal edges'at 'least two segments of which areintegr'ally joined, .andiwherein theangles formed 'between'adjace'nt segments are equal, theaxesof 7 a V V Vlongitudinal edges thereof.

the "respective segments"progressively, converging uni form'lyjaboutlan'ditowar d the longitudinal axis "of the structuralunit j 3.]An "elongated h' 'llow tapered structural unit comprising fouridenticallcylindrical segments, "each of said segments. progressivelydecreasing in width along the 7 length, i's'aidi'seg'ments 'beingjoinedto adjacent segments the respective segments intersecting thelongitudinal axis of the'stru'ctural'unit'at thefba'seithereof.

v '4. An *elongatedftape red structnrahunifcomprisingra pluralitypflongitudinally extending cylindrical surfaces welded together at the"opposite longitudinal margins thereof, eachjbf said' surfaces ihavingthe configuration of a' tapered segment era right circularcyli'ridenbent inwa-rdly alongan element of the cylinder intosymmetrical 'wing elements, and each of said wing elements having theconfiguration of"asegment"of'a' cylinder, the axes-of said wing elementsprogressively converging uniformly about and toward the longitudinalaxis of the structural unit.

5. The method'for' forming anelongated tapered structural unit whichcomprises shaping a plurality of blanks each into the configuration of atruncated isosceles triangle,;forminglsaid'blanks'into convex memberswhich are segments of a cylinder, folding said convex members along therespective centerlines' thereof into symmetrical e 7 Wing elements whichare segments of a cylinder, and welding said convex members together atthe meeting- 6liThe method for .manufactuiinglan elongated, ta-' peredstructural .unit which comprises shaping a pair of blanks into theconfiguration'of a truncated isosceles tri- V 7 angle, forming saidblanks into convex members'which V are segments of ajcylinder, foldingsaid Icnnvexelem'ents along there spective centerlines.'thereof 'intosymmetrical f 3 wing elements 'the 'chords ofi whichin cross section areperpendicularjjand welding said COI1YeX II lIIlbI'SfO- gether'at lthemeetingopposite longitudinal edges. 1 I

, ReferencesiCited inane "file'of this": patent i a 1 NiTEn STATESZPATENTS f .noREr N PATENTS

